Solar navigator



Dec. 2l, 1937. T E| |E| 2,102,587

` SOLAR NAVIGATOR Filed NovflO', 193s i 6 sheets-sheet 2 SOLAR NAVIGATOR Filed Nov. e10, 1936 6 Sheets-Sheet 5 A rroR/VEM Dec. 21, 1937. .T. ELM-:L

'SOLAR lNAVIGATOR Filed Nov. 1o, 1936 6 Sheets-Sheet 4 vDec. 21, 1937. T, E| |E| A 2,102,587

SOLAR NAVIGATOR Filed Nov. 10, 1936 I 6 Sheets-Sheet 5 ,eas Y T M I/v VEN TOR Leo/v 7.' /EL BY A TToR/VEK 7 6v .w u t L 2, e Rm w .0 m 0,. E .l TE N 2, Mr R WM. m Mmv IEV .A 6 LML] 8 l# 6 3 R 9 L m 1 5 E H o, o. .1 n 1 Ile E m MW? 1mm ,w A 4 L L d 0,/ w m mw m.. w 66 2 /3 so a 0 a am f a@ 7 a nu 3 9 7 l. O 0 2 L. 2 2 i 2 Patented Dec. 2l, 1937 lLeon LElieL Pasadena, Galli'. Application November 10, 1936, Serial No. 110,083

21 Claims.

My invention relates to navigation instruments, and relates in particular to a navigator for aerial vehicles having means for reference to the sunl and to the ground for maintaining an established will be imparted to the sun reference member. In the preferred practice of the invention hereinafter disclosed, the sun reference member comprises a solar compass adapted to receive rays or selected course of travel. from the sun, and having therein light responsive 5 Although the utility of my invention is not signal means which will cooperate in the produclimited, its present greatest value is in the navition of sensible signals for guidance of the pilot gation o i airplanes employed in aerial map makas the result of the change of position or condiing, wherein it is desirable to ny a course contion of suns rays received within the solar comsisting of a straight line to a degree of accuracy pass structure. beyond the ability of the ordinary pilot without Itis a further object of the invention to prospecialized instruments. The conventionalnvide a device of the character set forth in the struments ordinarily found on the panel of the preceding paragraph having a solar compass con-I airplane or other aerial vehicle do not give the nected with a ground reference member, and precision necessary for straight course flying. means for adjusting the solar compass for use in l The compass, for example, indicates only the different latitudes and longitudes, and having a direction in. which the airplane is headed and convenient means for making latitude and 10ngi does not take into considerationl factors which tude adjustments during ight of the aerial enter into the determination of the movement of vehicle in which the navigator is mounted. the aerial vehicle relative to the earth, for It is a further object of the invention to proexample, drift and changes in wind direction and vide a navigator including a solar compass and a velocity, ,which the pilot can only compute. This ground reference member, together with means instrument is suitable for night from town to for so mounting the solar compass that in proper town where the departure of a few miles from straight line ilying of the aerial vehicle the sun the absolutely straight coursebetween the towns compass will be directed at the sun in a manner is of no great consequence, but for the reasons set t0 reCeiVe SUIIS rays in a prescribed pOStOD, the forth above Compasses are not suillcient for progI'Ound `reference member being adjustably 00nducing the type of flying required in aerial map nected to the sun compass so that it may be set photography, the result being that pilots engaged at a desired course when the sun compass is in in this activity have had to depend upon instinct a position to receive rays from the sun, and signal and such instruments as have been available, means Operating alliiOmatiCally When the Sun Such, for example, as drift indicators. compass is moved from the herein stated position,

It is an object of the present invention to prosuch signals pl'OVidiHg informaiin fOr guidance vide a navigating device by which greater preof the pilot in the operation of the aerial vehicle.

y cision in the adherence to a desired course may be It iS a further ObJ'eGt 0f the iDVeIltiOrl 110 DIO- 35 obtained. vide a sun compass with a remote direction in- Ii; is an object QfA the invention to provide a dicator for use as a precision compass forv general navigator for aerial vehicles having a grund use. reference member adapted to indicate the direc- It iS a further Object 0f the nveniin t0 DTO- tion in which the aircraft is moving over the Vide a mea-DS 0f determining latitude and 1011i 40 ground, and means cooperating with the ground 'tude from a Single solar Observation reference member for imparting infomation to Further objects and advantages 0f the inventhe pilot of the aerial Vehicle when the direction tion Will be made evident throughout the fOlIOW- 'of travel over the ground varies from the desired ing Part 0f the Specification.

i' course, thereby enabling the pilot to correct his Referring t0 the drawings, Which are fOr lllus- 45 direction and condition of night. trative purposes only.

It is also an object of the invention to provide Fig. 1- is an assembly View showing 2 manner an aerial navigator of the character described in which the solar navigator may be mounted on having a sun reference member cooperating with an aerial vehicle, certain parts being rotated out a ground reference member adapted to be adof their normal operating positions so that they justed relative to objects visible on the ground, may be readily seen. the sun reference member and the ground refer- Fig. 2 is an enlarged, partly sectioned view of ence member being 'connected together so that the head of the device, with certain parts thereof movement of the ground reference member to rotated out of their normal positions of operas adjust it in a desired relationship to the ground tion so that these parts may beclearly seen.

Fig. 3 is a view, partly in section, taken substantially as indicated by the line 3-3 of Fig. 2. Fig. 4 is a fragmentary sectional view taken as indicated by the line 4-4 of Fig. 3. Fig. 5 is an enlarged, partly sectioned view .taken as indicated by the line 5-5 of Fig. 2.

Fig. 6 is an enlarged, partly sectioned view taken as indicated by the line 6-6 of Fig. 2.

Fig. '1 is an enlarged face view of the mirror of the sun compass.

, Fig. 8 is an enlarged sectional view taken as indicated by the line 8-8 of Fig. 2.

Fig. 9 is an enlarged sectional view taken as indicated bv the line 9--9 of Fig. 2.

Fig. .10 is a fragmentary elevation of Fig. 8. Fig. 11 is an enlarged cross section taken as indicated by the line II-II of Fig. 1.

Fig. 12 is a fragmentary cross section taken as indicated by the line I 2| 2 of Fig. 11.

Fig. 13 is an enlarged crossA section taken as 'indicated by the line l3 -|3 of Fig. 1.

Fig. 14 is an enlarged cross section on a plane represented by the line |4-I4 of Fig. 1.

Fig. 15 is an enlarged fragmentary cross section taken as indicated by the line |5|5 of Fig. 14. v

Fig. 16 is an enlarged fragmentary cross section taken as indicated by the line I6-I6 of Fig. 14.

Fig. 17 is an enlarged elevational view taken from a position indicated by the line I1-I1 of Fig. 14.

Fig. 18 is a diagrammatic view illustrating'conditions involved in the use of my invention.

Fig. 19 is an electrical diagram showing the I photronic cells and their connection with a galvanometer.

Fig. 20 is an electrical diagram of the hook-up for the gyroscope.

To illustrate a manner in which my device may be mounted in an aerial vehicle, in Fig. 1 I show a roof and a floor 3l of an airplane fuselage, there being vertically aligned openings 32 and 33 respectively in the roof and floor members 30 and 3l. Thenavigator includes a clock-driven sun compass 34 having adjustment means which will be later described in detail, means preferably including a yoke 35 for supporting the sun compass 34 so that it may be rotated on a vertical axis,a course determining means 36 adapted to be set to the azimuth of the course to be followed, and a course checking means 31 including a ground sight 38 which will show whether or not the determined course is being followed or whether the aerial vehicle isdrifting from its intended course.

The yoke 35, as best shown in Figs. 1 and 2, comprises a. bottom wall 39 having a centralized bearing member 40 which under proper conditions of operation of the navigator is on a vertical axis, and a pair of arms 42 extending upwardly from the ends of the bottom wall 39 and having openings 43 in the upper ends thereof adapted to receive horizontally aligned shaft members 44 forming a part of the head support 45 for the navigator. As shown in Fig. 2, the bearing member 48 has a wall 46 carrying frictlonal bearings 41 supporting a sleeve 48 which forms the upper part of a vertical column or hollow shaft 49 which supports the elements 36 and 31 and connects the same to a. yoke 5| in which the sun compass 34 is swung in an adjustable manner. The upper end of the sleeve 48 has a flange or collar 52 which rests against the bottom wail s: of the yoke 5l.- Gonneton is made between the yoke 5I and the sleeve 48' by a stem 54 which has a shrink or press fit in an opening 55 in the bottom wall 53 of the yoke 5I. The yoke 5I includes a. pair of arms or forks 56 and 51 extending upwardly from the ends of the bottom wall 53.l 'I'he upper ends of the arms 56 and 51 have horizontally aligned bearings 58 and 59 which receive hollow shafts 60 and 6| which project outwardly from a casing 62 of the sun compass 34. The inner ends of the shafts 60 and` 6I are fixed in bosses 63 projecting outwardly from the casing 62 by means of set screws 64. T'he lower end of the casing 62 is closed by a Wall 65, and to this wall a clock 66 is secured so that it will form a part of the suny compass structure.

The clock 66 is preferably of spring driven type and has a setting knob 61 projecting centrally from the face 68 thereof, this knob 61 being preferably mounted on the shaft of the clock which carries the minute hand, whereby the setting of the knob will directly move the minute hand from one position to another.

The casing 62 has a top or front wall 69 from the center of which a tubular wall 10 projects. This tubular wall 10 has internal threads 1l which adjustably receive a lens supporting member 12 carrying a lens 13 defining an optical axis A-A extending axially with respect to the casing 62 and the wall 10. A mirror support 14 is mounted on the wall 10 so as to revolve around the axis A--A, and includes a ring 15 which is mounted on the tubular wall 10 by bearings 16. A bracket 11, Figs. 2, 5, and 6, is connected to the ring 15, and forks 18 project from the bracket 11 in parallel relation to the axis A-A. The outer ends of the forks 18 have openings 19 disposed in a plane normal to the axis A-A, these openings 19 receiving flanged bushings 80 which carry a mirror or reflector shaft 8i which is flattened on one side thereof, as indicated by 82, so that the inner end of the mirror supporting plate 83 may be secured thereto by the use of screws 83a. A mirror or sun reflector 84 is employed having relieved corners at one end thereof and a notch 86 at the opposite end thereof. The mirror 84 is held against the face of the-p1ate 83 by means of clips 61 which flt the corners 85 of the mirror and a screw 88 which passes through the notch 86 thereof. For the adjustment of the mirror 84, duplicate means are provided for rotating the shaft 8l on its axis. Each of such meansincludes a lever 89 which may be locked upon an end of the shaft 8i by means of a locking screw 90. Cooperating with each of the levers 89 is a plate 9| secured to a bracket fork 18 by means of screws 92. Each plate 9| is provided with'a scale 93 graduated to forty half-degrees on each side of a zero point. Each lever 89 has a cooperating Vernier scale 94, and when the zero point of the Vernier scale 94 coincides with the zero point of its cooperating scale 93, the shaft is adjusted by rotation to bring the mirror 84 into a position crossing the axis A-A at an angle of 45. Each lever 89 has an adjusting and locking means consisting of a plate 95 which slides across the face of the cooperating plate 9| and is adapted to be locked against the face of such plate 9| by a locking bolt means 96 including a screw 91 and a nut 98 which travels along an arcuate slot 99 in the cooperating plate 8|. arcuate form, is secured to each lever 89 by means of screws IM in a position to extend over one portion of a plate 95, there being a locking screw A slotted plate |00, of.

|02 and a guide screw |03 extended through the slot |04 of the plate |00 into threaded engagement with the cooperating plate 95. Each plate 95 'carries a post or stud |05 through which avernier adjustment screw is threaded, and each lever 89 has mounted thereon a post |01 having a slot |08 in its outer end through which an end portion |09 of a vernier adjustment screw |06 passes, there being collars ||0 on the end portion |09 to engage opposite sides of the post |01. Before adjusting the mirror 84 to a desired posi.- tion of use, all of the screws 91 and |02 are loosened so that as the levers 89 are swung, the plates 95 will slide upon the plates 9|. The levers are then swung to approximately the ciesired position, and one of the locking screws 91 is tightened. lI'hen the Vernier adjustment screw |06 adjacent the locking screw 91 which has been tightened is operated to move the levers `into a nal position of adjustment, after which the remaining screws 91 and |02 are tightened.

As shown in Figs.- 8, 9, and 10, a drive shaft lll projects from the clock 66 and across the outer face of the casing 82.- This shaft is supported by bearing members ||2 which are secured to the casing 82 by screws H3. A small gear lid on the upper end of the shaft engages an idler gear ||5\mounted on the upper end of a shaft i6 carried by bearing members H1. The upper part of the idler gear ||5 engages a gear ||8 which is secured to the lower portion of the ring 15, so that the mirror support 10 will be rotated by the clock 66 to keep the mirror 84 pointed at the sun during the operation of the navigator in one hemisphere.

When'the navigator is used`in the other hemisphere, the direction of rotation of the mirror support 14must be reversed. This is accomplished by moving the shaft ||6 and the gear ||5 to the position indicated by dotted lines I|6a, and then moving the shaft upwardly so that the gear I4 at the upper end thereof will engage the gear |8 directly instead of through an idler.

'I'he shaft member 60 which projects from the casing 62 has a latitude segment ||9 secured thereon, this segment ||9 having a latitude scale of a range of slightly over 90. An index plate |2| is secured to the arm 56 of the yoke 5|. The segment ||9 is mounted on the shaft 60 in such position that zero of the scale |20 will coincide with the index mark |22 of the member |2| when the axis A-A, Fig. 2, is disposed in a plane 90 from the axis of the sleeve 49, this being the position of the axis A-A when the navigator is being used at the equator or zero latitude. For rotation of the casing 62 on the axis defined by the shaft members 80 and 6|, a gear segment |23 is fixed on the outer end of the shaft member 6|. This gear segment |23 is engaged by an idler gear |24 supported by a journal |25 which is secured to the'arm 51 of the yoke 5| by means of a plate |126. A shaft |21 is mounted in the lower part of the yoke 5|, and on its outer end carries a gear |28 for driving the idler |24. The inner end of the shaft |21, as shown in Fig. f1, is supported by a bearingmember |29 and has a worm gear |30 thereon engaged by a worm |3| mounted on the' upper end of a vertical shaft |32, which shaft extends centrally within the sleeve the remaining parts of the column 49. The lower portion of this column 49 consists of a tube |33 and as shown in Fig. 12 has a bushing |34 atv its lower end to provide a bearing for the lower portion of the shaft |32. The lower extremity of the shaft |32 projects vfrom the bearing |34,

48 and and a knob |36 is secured thereon by suitable means such as a set screw |31. Associated with the knob |36 is a ilange |38 having graduations |39, Fig. 13, on the upper face thereof each representing av quarter-degree of rotation of the solar compass 34' on the shaft members 60 and 6|. The lower end of the tube |33 has a fitting |40 secured thereon providing an index member |42 relative to which the graduations |39 of the l'member |38 move when the shaft |32 is turned. The fitting |40 is provided with slots |43, and screws |44 traversing these slots are employed to clamp the tting on the lower end of the tube |33. The upper end of the tube |33 may be connected to the lower end of the sleeve 48 by means of a member |45, Fig. 2, having internal threads |46 for engagement with threads |41 on thelower end of the sleeve 48.

By means of a support |48 mounted on the wall 65, shown in Figs. 2, 8, and 9, a light dividing means |49 is secured within the casing 62 in a position centralized on the axis A-A. This light dividing means includes a bottom wall |50, a, pair of opposed side walls |5|, and a top wall |52 secured together by means of screws |53. Between the sidewalls |5| diagonal mirrors |54 and |55 are extended, these mirrors converging upwardly and lying in planes which intersect on the axis A-A and are each disposed at an angle of to theaxis A--A. At the outer edges of the mirrors |54 and |55, translucent walls |56 are supported as shown in Fig. 2. The upper wall |52 of the light dividing device has an opening |51 therein across which a translucent member or lter |58 is extended, as best shown in Figs. 8 and 9. By means of supports |59 mounted on the wall 65, photronic cells |60 and |6| are secured on opposite sides of the light dividing means and in positions adjacent the translucent walls |56. C0- operating with the supports |59 are spring clips |62 which are mounted on the front wall 690i the casing 62 in positions to bear against the portions of the cells |60 and |6| disposed oppositely from the supports |59. v

As shown in Figs. 1, 11, and l2, a circular plate |63 is secured near the lower end of the tube |33. The plate |63 may be fixed rigidly on the tube the lateral axis dened by` |33 by use of a split bushing |64 which is threaded into a tapered opening |65 in a boss |66 which projects downwardly from the plate |63, and a set screw` |61 may be provided to lock the member 64 in place. Above the plate |63, so as to restupon the upper face thereof, a spider |68 is disposed around the tube |33, this spider |68 having an upwardly projecting boss |69 with a bore |10 in which a split sleeve |1| is placed so as to engage the tube |33. Clamping screws |12 are threaded through the boss |69 so as to engageV the sleeve |1| to clamp the same on the tube |33 and thereby prevent rotation vof the spider from` a desired position. The peripheral portion |13 of the plate |63 is provided with a circle |14 graduated to degrees, and a reference mark |15 is provided on the spider |68 by use of a plate |16. The zeropoint |11 of the circle |14 is disposed in a plane which radiates from the axis dened by the column 49 and is disposed at an angle of 90 to the axis defined by the shaft members 60 and 6|.

From the ends |18 of the arms |19 of the spider" plate IBI, Figs. 1 and to the -axis of the column 49, plates provided on the upper and 'lower ends of the 14, which is perpendicular bars whereby to connect such ends of the bars |80 by means of screws |83 respectivelyto the spider |68 'and the plate |8|. As shown in Figs. 14 .to 16 inclusive, the Aplate |8| carries a ring |84 which provides an openingv |85 through the plate, this opening |85 being preferably circular and aligned with the axis of the column 49. The extending portion |86 of the plate |8| carries a gyroscope |81, the details of which are not shown since gyroscopes and their characteristics are well known. The gyroscope has a shaft |88 which projects along and is rotatable upon -an axis perpendicular to the axis defined by the column 49. This shaft |88 has a bracket |89 which carries the ground sight 38 and also has a level |90 thereon for observing or checking from time to time the level of the ground sight 38. As shown in Fig. 1, the ground sight'38 comprises a conical shell |9| having an objective lens |92. As shown in Fig. 14, the shell |9| has a'translucent plate |93, such as ground glass, on -which the lens |92 focuses an image of the terrain over which the flight is being made. This translucent plate or screen |93 has parallel lines- |94 which are likewise parallel to the shaft |88 on which the ground sight is mounted. These parallel lines |94 when in their normal position are likewise parallel to a radial line or plane defined by the index mark |15 of the spider |68. f

As shown in Figs. l5 and 16, the ring |84 has a ange |95 projecting outwardly from the lower portion thereof so as to engage an annular channel |96 formed in a guide ring |91 which is made from two parts, namely, a lower ring element |98 and an. upper ring element |99, secured together by `screws 200. The guide ring |9-1 is connected by means of a bracket 20| with a trimming device 202, shown in Figs. 1, 14, 15, and 1'1. As shown in Fig. 15, the outer portion of thebracket 20| is held in a recess 203 in the ring element |98 by screws 204,- and the bracket has a vertical wall 205 with a vertically elongated opening 206 therein.

The trimming device 202 includes a base 201 having an upwardly directed wall 208 along one edge thereof, this wall 208 having a longitudinal slot 209 therein.- 'I'he base 201 is secured to the floor 3| of the aerial -vehicle at one side of the opening 33, and with the wall 208 parallel to the longitudinal axis or line of ilightof the aerial vehicle. A traveling member or carriage 2|0 is mounted so as to slide along the wall 208. The carriage 2|0 comprises a bar 2| having threaded openings 2|2 receiving screws 2|3 which pass through the 'slot 209 of the wall 208, the body por.- tions 2| 4 of these screws sliding in the slots 209 and thereby guiding the movement of the bar 2| A rack 2 |5 is secured to-the lower edge of the bar 2| by use of rivets 2|6, and in a position to be engaged by a pinion 2l1 mounted on a shaft 2|8 carried by a bearing block 2|9 in a position parallel to the plate 201 and `perpendicular to the wall 208. A bevel gear 220 mounted onthe end of the shaft 2|8 opposite from the gear 2|1 is engaged by a bevel gear 22| xed on a vertical shaft 222 carried by a bracket 223 which is secured to the plate 201 by means of screws 24. A knob 225 is'secured to the upper end of the shaft 222 so as to rotate the Isame and to thereby transmit rotation through the bevelgears 22| and 220 to the shaft 2|8 which carries the gear 2|1 so that the gear 2|1 will move the rack 2|5, causing the car- Vriage 2 I0 to travel lengthwise of the opening 33 in the floor 3| of the aerial vehicle. The bar 2|| has a. vertical slot 226, and the carriage includes a contact rings 243 and 244 vertically slidable block 221 which, as shown ir Fig. 15, is of U-shaped form so as to provide a wall v 228 which is vertically slidable in 'the slot 226 oi shaft members 44 of the yoke 35. To permit such swinging movement of the guide ring |91 but to restrict the swinging movement thereof in a verf tical plane extending lengthwise of the aerial vehicle and coinciding with the center line C-C through the opening 33, a trimming device 202 has been provided in which the block member 221 may move vertically in the slot 226 of the carriage 2| 0, the block member 221 having the laterally directed screw 230 on which the bracket 20| may turn as the trimming device is employed to move the plate I8 between a position such as shown in full lines and a position indicated by dotted lines 23| in Fig. 14. The plate |8| and the ground sight 38 supported thereby may be rotated in the guide ring |91 from the position indicated in full lines in Fig. 14 to other positions such as suggested by dotted lines 234, as required in the operation of the device to be later explained. This rotation will produce a like rotation of the column 49 and thesun compass 34 on the axis of the column 49 owing to the rigid connection of parts as hereinbefore described. To show the amount of rotation of the plate |8| and the ground sight 38 relative to the lengthwise plane defined by the line C,C, a scale 232, graduated in degrees, may

- be inscribed in the ring |84 which is secured4 to the plate |8|, and an index mark 233 ma be rovided in the ring element |98 of the glide ging |91. A plate 235, carrying a locking screw 236, is mounted on the plate 8| in such position that the screw 236 will extend through an opening 231 -in the plate' and press a cup-shaped shoe 238 against the ring element |99 of the guide ring |91.

As shown in Fig. 19, the photronic cells |60 and |6| are connected in opposing relation to conductors 239 and 240 which connect through brushes 24| and 242 and contact rings 243 and 244 with conductors 245 and 248 which extend to an electro-sensitive indicator, such as a galvanometer 241. As shown in Figs. 2, 3, and 4, the are mounted in a nular insulating member 248 carried in the ilxlpilr face of the bottom wall 39 of the yoke 35, and

terminal screws 249 and 250, Fig. 3, are provided for connecting the conductors 245 and 246. The

brushes 24| and 242 are carried in brackets 25| mounted on 'the lower member 53 of the yoke 5|.

As shown in the electrical diagram, Fig. 20, the gyroscope |81' includes a motor 252 included in a circuit 253 with a source of electric current such as a. battery 254 when a switch 255 is closed. A

rheostat 256 is provided in the circuit 253 for control of electrical energy to the motor 252, and a.

.voltmeter 251 is connected ln parallel with the circuit 253 to show the voltage applied to theV motor under control of the rheostat 256.

The operation of the navigator will be understood from the following. Before the night is started, the cooperating parts are adjusted to positions governed by conditions under which the flight is` to be made. For example, the sun compass 34 is swung on the lateral axis defined by the shaft members 60 an 6| to a position governedyby the latitude, or 4 mean latitude, of the sun. Therefore, as long as along the axis A-A one of the photronic course Acontemplated for the flight, so that when` the axis A-A of the sun compass is pointing in true polar direction, for example, true north, it will likewise be parallel to the axis 260 of the earth 26| indicated in the diagrammatic view, Fig. 18. For example, if the mean latitude of the course is 30 north of the equator 262, as indicated at 263 in Fig. '18, the sun compass will be set to a position at an angle of v60 from the axis B-B, Fig. 1, as illustrated in Fig. 1, this setting of 30 being indicated on the latitude scale |28. The suns rays may at the season of the year during which the flight is made have a north declination indicated by the angle d. If such is the case, the mirror 84 must be set in accordance with this declination by moving the lever arms 89 associated with the mirror 84 relative to the declination scale 93 into the proper position in accord- ,ance with the declination d. The mirror 84 is then set for longitude, which is done by setting the clock to solar time for the location at which the photographic operations are conducted. This is done by determining the standard time of the standard time section in which the location is included, and then computing the'solar time of the location by adding thereto or subtracting therefrom, as the case may be, in accordance with the distance of the location from the meridian on which the standard time of the section is based and in accordance with the existing equation of time value obtained from the Solar Ephemeris tables. Then, at noon, withthe axis A-A pointing north and also parallel to the axis 260 of the earth, the suns rays 263 will be reiiected by the mirror 84 into the casing of the sun compass along the axis A-A, providing that the reflecting face of the mirror 84 is disposed perpendicular to a plane which coincides with the axes A-A and 260. Furthermore, as the earth V26| rotates, the clock 66 willrotate `the mirror support in contrary direction so-that' the mirror 84 will continue to point at the sunyor, in other words, will continue to be perpendicular to a plane coincid axis A--A and passing through the the foregoingconditions are maintained, the suns rays will be re flected by the `mirror 84 along the axis A-A into the interior of the sun compass casing 62; but should the sun compass 34 be rotated from the previously prescribed position, for example, on the axis B-B so that the axis A-A will swing from true north, the suns rays reflected by the mirror 86 will not pass into the suncompass 3d butv will be deiiected to one side or the other ofthe axis A-A in accordance With the direction in which the axis A-A is displaced. This will result in more light striking one of the diagonal reflectors ISL-|55 than strikes the other of such reiiectors, with the result that cells |60| 6| will receive ing with the Vnometer `241 is preferably mounted in the control chamber, or cockpit of the aerial vehicle, in viewmf the pilot to indicate to him the need for a change in the direction of travel of the aerial vehicle, and likewise the approximate magnitude and direction of the needed vchange .in rtravel of the aerial vehicle.

other and will accordingly The setting of the mirror support 15 for longitude, or so that the mirror 84 will point at the sun, is accomplished by setting the clock 66 by rotation of the knob 61. The clock 66 is connected to the mirror support through the gear means previously described, in such relation that when the clock reads I2 noon, the mirror support will be in a position 90 rotated from the position in which it is shown in Fig. 2, or in a p0- stion substantially as shown in Fig. l, wherein the face of the mirror 84 will be parallel to the axis dened by the shaft members 60 and 6| and consequently perpendicular to a plane which is in turn perpendicular to the axs- D-D. Thereiore, at 12 noon, actual time, the mirror will point directly at. the sun if the clock likewise reads 12 noon, and will also point at the sun at any time during the day provided the reading of the clock shows the solar or actual time, which may be readily computed, and also provided that the axis A--A points true north and is parallel to the axis of the earth and also the mirror 84 is set for the existing declination of the sun.

The direction of the course to be followed will then be set on the scale |13-0f the member |63. If the direction of the flight in the northern hemisphere is to be true north, the scale l|13 will be set at zero, as shown in Fig. 11. For other directions of flight, the member |68 will be set on the scale I 13 in accordance with the angle and directionvof flight relative to the previously mentioned true north flight. According to the lforcgoing, if theilight is to be conducted southwardly along a true north and south line, the solar compass 34 and the course checking means 31 willv be in the correlative positions in which they are shown in Fig. 1; but, during the time. the aerial vehicle is headed in the direction of true south, the roof 30, the floor 3|, the yoke35, the yoke supporting means, and'the trimming means 202 will be rotated 90 around the axis B-B for the reason that at this time the center line C--C will extend in the same direction as the axis A-A of the sun compass 34, or, in other words, will be in the same vertical plane as the axis AA.

Assuming now that the airplaneis ying south and is truly following its prescribed true north to south course without drifting, the image appearing on the screen or plate |93 of the ground sight 38 will move parallel to the lines |94. In other words, an object of the image which is observed to lie upon one of the lines |94 of the screenV |93 will move along such line |94 so lo'ng as the airplane is on its course. Should the airplane move over the ground in any direction` other than the desired course, the observedobject of the image will move at an angle relative to the line on which it was originallyobserved. The observer or navigator, noting the drift of the object from the desired line of movement on the screen |93, will rotate the course Vchecking means 31 to bring the lines- |94 into a position parallel to the observed lineof movement of the object on the screen. This rotation-of the member 31 will cause a like rotation of the column 49 andthe sun compass 34, with the result that the beam of light reflected by the mirror 84 will move to one side of the axis A-A and produce a signalor ilow of electric energy which may be used in the control or directing ofthe iiightof'the aerial vehicle. In the preferred practice of the inven- 'tion the movement of the beam of-light'to-one' side of the axis A-A changes the energization of the photronic cells and causes a flow of current through the galvanometer 241 so that the indicator '265 thereof will move to one side of its central position, thereby indicating to the pilot thatv the direction of travel of flight should be changed.v The galvanometer 241 is preferably connected with the cells |60 and |6| in such a manner that the direction of movement of the indicator 265 from central position will indicate the direction in which the iiight is in error. The pilot then slowly turns the airplane until the galvanometer 241 reads 0.

Atmospheric conditions are not ordinarily such that the longitudinal center line of the airplane may be maintained on the line of iiight, but-as a general rule winds or air currents will be encoun-` tered which are diagonal to the intended line of night, with the result that the longitudinal center line of the airplane must be oriented to compensate for the drift of the air currents or winds. However, as the center line C-C, Fig. 14, is rotated or swung from one side to the other of the prescribed course, the course checking means 31 and the remaining parts of the navigator which are'rigidly secured thereto will be rotated relative to the guide ring |91 so as to keep the lines |94 of the screen |93 parallel to the direction of movement of the image of the underlying terrain which appears on the scene |83. It will be perceived that in the flying of the airplane along a north to south course, eastward and westward winds will make it necessary to point the nose of the airplane respectively westwardly and eastwardly, which is a condition referred to as "crab Other than for the normal functions of the pilot ln operating the airplane and the acts of the navigator in observing the image on the screen |93 and rotating the course checking means 31, as previously described, the navigating device will automatically direct the flight of the airplane so as to produce a reasonably close adherance to the selected course.

As the latitude of the airplane changes, periidic adjustments of the latitude setting of the :un compass must be made. 'Ihis is accomlished by rotation of the handwheel or knob 36 at the lower end of the column 49. If the lourse is such that the longitude of the airplane hanges, periodic adjustment of the clock 66 must e made, so that the hands of the clock will inicate true solar time within prescribed limits. .'hese adjustments of time and latitude are necssaryto keep the mirror 84 in proper position o reectraysfrom the sun along the axis A-A 'hen the axis A-A is parallel to the axis of the arth. Adjustment of the mirror for declination f the sun need not be made oftener than once day.

'I'he sun compass may beregarded as a sunointer, the disposition of ,the pointer being in ie direction of the received Sunbeam. Since ie pilot steers the aircraft in accordance with continuously increasing or decreasing angle tween the disposition of the received Sunbeam nd the direction of ground travel, it is apparent iat my device incorporates a variable angleening means, one leg of which comprises the round sight adapted for alignment with the cliection of ground travel, and the second leg com- .'ising the sun compass regarded as a pointer rected at the sun. The angle between the two gs is changed by the clock at a rate compenting for rotation of the earth, so that the dissition of the ground sight with respect to lrth is constant so long as the other leg is kept lgned with the sun.

While the above described application of this invention pertains to the navigation of aircraft, the instrument may also be adapted to the navigation of other types of vehicles; and by utilizing a true north setting and a known declination and Greenwich time, the instrument obviously, with a slight change of the mirror and photronic cell disposition, could be used for determining the latitude and longitude of the point of observation. For example, in determining longitude and latitude, the device may be used in the following manner. such as a gyroscope compass, for example, may be used to position the yoke so that the axis A-A of the sun reference member will swing on a plane which coincides with the earths axis, or, in other Words, a vertical plane which also extends true north. The mirror 84 will be then adjusted for the proper declination of the sun and locked in this position by means oi.' the screws 91 and |02. After this the sun .compass 34 will be rotated on its horizontal axis D-D, and the mirror support will be rotated on the axis A-A.

until rays of light received by the mirror 84 from the sun will be reected valong the axis A-A, which condition will be shown by a centralized position of the indicator 265 of the gaivanometer 241. When the foregoing adjustments have been made, the scale will indicate latitude and the clock 66 will show true solar time from which longitude may be readily determined by comparison with Greenwich time or standard time. v

Although I have herein shown and described my invention in simple and practical form, it is recognized that certain parts or elements thereof are representative of other parts, elements, or mechanisms which may be used in substantially the same manner to accomplish substantially the same results; therefore, it is to be understood that the invention is not to be limited to the details disclosed herein but is to be accorded the full scope of the followingfclaims.

I claim as my invention:

1. In a navigator of the character described, for use in an aerial vehicle, the combination of a ground reference member having means for adjusting it relative to the aerial vehicle and so as to follow a selected object on the ground as the aerial vehicle moves relative to the/ground; a sun reference member connected to said ground reference member so as to be moved thereby, said sun reference member having means which correspond to a prescribed azimuth when said aerial vehicle is moving on its course; and photoelectric means operative by the suns rays in response to the movement of said sun reference member from its prescribed azimuth position to give a sensible indication that said sun reference member has been so moved by said ground reference member.

2. In a navigator of the character described, for use in an aerial vehicle, the combination of: a sun compass adapted to receive rays from the sun; means for mounting said compass in said aerial vehicle so that said rays received from the sun, will be in a prescribed position when said compass is in `a prescribed position relative to north, and so ,that said rays will move out of said position when said compass is moved fromits prescribed position; and means operative in response to the movement of said received sun .rays out of said prescribed positionto produce an indication of said movement thereof.

3. In a navigator of the character described, for use in an aerialv vehicle, the combination of:

Sonie suitable means,

, supporting said a sun compass adapted Ito receive rays from the sun; means for mounting said compass in said aerial vehicle so that said rays received from the sun will be in a prescribed position when said out of said prescribed position to produce an indication, sensible to the pilot of the aerial vehicle, l

of said movement thereof.

4. In a navigator of the character described, the combination of: a sun compass having means for mounting it so as to move relative to horizontal and vertical axes; means for adjustably holding said sun compass at an angle to vertical selected in accordance with the latitude at which said compass is being used; aground reference member; and means connecting said ground reference member to said compass.

5. In anavigator of the character described, the combination of: a sun compass; means for supporting said compass so that it will swing on a lateral axis; a second supporting means for supporting said first named supporting means so that it will rotate relative-to a vertical axis; a ground reference member; and means for adjustably connecting said ground reference member to said last named supporting means.

6. In a navigator of the character described, the combination of a sun compass; means for supporting said-compass so that it will swing on a lateral axis; a second supporting means for supporting said rst named supporting means so that it will rotate relative to a vertical axis; a ground reference member; and means vfor adjustably connecting said `ground reference member to said last .named supporting means, said connecting means including a deviceI operating to automatically maintain said ground reference member level in at least one direction,

7. In a navigator of the character described, the combination of: a sun compass; means for compass so that it will swing on a lateral axis; a second supporting means for supporting said first named supporting means so that it will rotate relative to a vertical axis; a ground reference member; means for adjustably connecting said ground reference member to said last namedsupporting means, said ground reference member having a viewing element whereby the image of the ground is visible to an observer and having a reference mark vviewed with the image of the ground and appearing to move relative to the ground, said ground reference member being also adjustable with relation to the ground by rotation thereof around said vertical axis whereby like rotation is imparted to said last named supporting means; and means cooperating with said compass to indicate its p0- sition.

8. A sun compass of the character described, including: a light receiving member; means for supporting said light receiving member so that' it may move through a position wherein light rays from the sun will be received in a prescribed position in said light receiving member; light responsive means. adjacent said prescribed position so as to receive rays entering said light receiving member; and indicating means associated with said light responsive means.

9. A sun compass of the character described, includingra light receiving member; meansfor supporting said light receiving member so that it may movethrough a position wherein light rays from the surrwill be received in a prescribed position in said light receiving member; light responsive means adjacent said prescribed position so as to receive raysentering said light receiving member; and electrical indicating means connected to said light responsive means to show the energization thereof by suns rays.

10. A sun compass of the character described, including: a light receiving member; means for supporting said light receiving memberso that it may move through a position wherein rays from the sun will pass along an established path in said light receiving member; photronic cells.

lying on opposite sides of said established path; and electrical means connected to said photronic cells and indicating the state thereof.

. 11. A navigator of the character described, having in combination: variable angle-defining means having one leg for alignment with adirection of travel and a second leg'for aligmentwith the sun; and means to vary the angle of said legs in compensation for rotation of the earth.

12. A navigator of the character described, having in combination: variable angle-defining means having one leg for alignment with a direction of travel and a second leg for alignment with the sun; means to vary the angle of said legs in -compensation for rotation of the earth; and

means to indicate deviation of said second leg from alignment with the sun.

13. A navigator of the character described; having in combination: 'variable angle-definingk means having one lleg for alignment' with a direction of travel and a second leg for alignment with the sun; means to vary the angle of said legs in compensation for rotation of the earth; and photo-electric means responsive to the rays from the sun to indicate deviation of said second leg from alignment with the sun.

14. A navigator of the character described for craft, said navigatorhaving in combination: a course determining means revolvably mounted on the craft; a sun-pointer revolvably related to said means and adapted to receive rays from the sun when aligned with the sun; means to rotate said sun-pointer relative to said course determining means at the rate of the earths rotation in a direction to keep the compass direction of said course determining means constant so long as said pointer is aligned with the sun; and photoelectric means responsive to said rays to indicate to the pilot of the craft deviation of said sunpointer from normal alignment with the sun.

15. A navigator of the class described for aircraft, said navigator having incombination: a course determining means revolvably mounted on the aircraft; a sun-pointer revolvably related to said means and adapted to receive rays from the sun when aligned with the sun; means to rotate said sun-pointer relative to said course determin-y ing means at the rate of the earths rotation in a direction to keep the compass direction of said course determining means constant so long as said pointer is aligned with the sun; a ground sight movable into alignment with the direction of ground travel, said ground sight being operatively connected with said course determining means; and means to indicate to the pilot of the aircraft deviation of said sun-pointer from alignment with the sun.

16. A navigator of the class described for aircraft, said navigator having in combination: a course determining means revolvably mounted on the aircraft; a sun-pointer revolvably related `to said means and adapted to receive rays from n determining means at the rate of the earths rotation in a direction to keep the compass direction of said course determining means constant so long as said pointer is aligned with the sun; a ground sight connected with said course determining means whereby said course determining means may be aligned with the direction of ground travel; and photo-electric means responsive to said rays to indicate to the pilot of the aircraft deviation of said sun-pointer from normal alignment with the sun.

17. In a navigator of the character described: a member revolvable about an axis parallel with the axis of the earth; a mirror revolvable with said member to reflect a beam from the sun alongV the axis of the member; and means to revolve the member: and mirror about said axis in compensation for rotation of the earth.

18. In anavigator of the character described: a memberrevolvable about an axis parallel with the axis of the earth; a mirror revolvable with said member to reflect a beam from the sun along the axis lofthe member;.means to revolve the member and mirror about said axis in compensation for rotation of the earth; and remote means to indicate to apilot deviation `of said member from a position refiecting said beam along its axis. l

19. In a navigator of the character described: a member revolvable about an axis parallel with the axis of the earth; a mirror revolvable with 'said member to reilect a beam from` the sun along the axis of the member; means to revolve the member and mirror about said axis in coml pensation for rotation; of the earth; Land photoelectric means responsive to said beam to indicate deviation of said member from a position reflecting said beam along its axis.

20. A navigator of the character described for air-craft, said navigatorhaving in combination: a course determining means revolvably mounted on the aircraft; a member revolvably related to said means and also revolvable about an axis parallel with the axis of the earth; a mirror revolvable withA said member to reflect a `beam from the sun along the axis of the member; means to revolve the member and mirror about said axis in Acompensation for rotation oi! the earth to keep the compass direction of said course determining means constant so long as said beam is reilected along the axis oi?` said member; a ground sight movable into alignment with the direction of ground travel, said ground sight being operatively `connected with said course determining means; and means to indi-l cate to the pilot of the aircraft deviation of said member from a position reflecting said beam along its axis.

`21. A navigator of the character described for aircraft, said navigator having in combina tion: a course determining means revolvably mountedon the aircraft; a member revolvably relatedto said means and also krevolvable about an axis parallel with the axis of the earth; a mirror revolvable with said member to reflect a beam from the sun along the axis of the member; means to revolve the member and mirror about said axisin compensation for rotation of the earth to keep the compass directionof said n Acourse determining means constant so long as said beam is reected along the axis of said member; a ground sight movable'into alignment l with the direction of ground travel, said ground sight being operatively connected with said course determining means; i and photo-electric means responsive to said beam to indicate to the pilot of the aircraft `deviation of said member froml a position reecting :the -beam along its axis.

LEON T. ELIEL. 

